Foamed article comprising filled perfluoropolymer composition

Abstract

The present invention relates to foamed articles, such as plenum cables jacketed with a composition comprising perfluoropolymer, inorganic char-forming agent, and polymeric dispersing agent, which passes the NFPA-255 burn test.

1 . A foamed, melt-fabricated article containing a composition comprising perfluoropolymer, about 10-60 wt % char-forming inorganic agent, and an effective amount of polymeric dispersing agent to disperse the char-forming inorganic agent in the perfluoropolymer during melt processing.  
   
   
       2 . The article of  claim 1 , wherein the polymeric dispersing agent comprises about 0.1 to 5 wt % hydrocarbon polymer that is thermally stable at the melting temperature of said perfluoropolymer, to total 100 wt % based on the combined weight of said perfluoropolymer, agent and hydrocarbon polymer.  
   
   
       3 . The article of  claim 1 , wherein the polymeric dispersing agent comprises 0.1 to 5 wt % fluoropolymer additive, to total 100 wt % based on the combined weight.  
   
   
       4 . The article of  claim 3 , wherein the fluoropolymer additive is selected from the group consisting of vinylidene fluoride/hexafluoropropylene (VF2/HFP) copolymer, tetrafluoroethylene/propylene (TFE/propylene) copolymer, vinylidene fluoride/hexafluoropropene (VF2/HFP/TFE) copolymer and tetrafluoroethylene/perfluoro(methyl vinyl ether) (TFE/PMVE) copolymer.  
   
   
       5 . The article of  claim 1 , wherein the article has a reduction in density of greater than 10% as compared to the unfoamed article.  
   
   
       6 . The article of claims  2  or  3 , which passes the NFPA-255 burn test.  
   
   
       7 . A melt fabricated article of  claim 1 , wherein said article comprises a cable jacket, tubing, profiles or tape.  
   
   
       8 . The article of  claim 1  wherein said agent is in the form of particles having a mean particle size of no greater than about 3 micrometer.  
   
   
       9 . The article of  claim 1  wherein said agent is metal oxide.  
   
   
       10 . The article of  claim 9  wherein said metal oxide is ZnO.  
   
   
       11 . The composition of  claim 2  wherein said hydrocarbon polymer is thermoplastic elastomer.  
   
   
       12 . The article of  claim 11  wherein said thermoplastic elastomer contains aromatic moiety.  
   
   
       13 . The article of  claim 2  wherein said composition is free of added antioxidant.  
   
   
       14 . The article of  claim 2  or  3  further comprising an inorganic phosphor in an effective amount to color said composition when subjected to excitation radiation.  
   
   
       15 . The article of claims  2  or  3  wherein said char-forming agent is ceramic microspheres.  
   
   
       16 . The article of claims  2  or  3  wherein the composition further includes a chemical blowing agent.  
   
   
       17 . A process for foaming the article of  claim 1 , comprising extruding the article in the presence of a foaming agent and obtaining as a result thereof said foaming of said article.  
   
   
       18 . The process of  claim 17 , wherein the foaming agent is a chemical blowing agent incorporated in the composition that decomposes to form a gas at the extrusion temperature.  
   
   
       19 . The process of  claim 18 , wherein the foaming agent is injected into the extruder.  
   
   
       20 . The process of  claim 17 , wherein said extruding the article is done in the absence of a nucleating agent.